Zuogui Jiangtang Jieyu Formula ameliorating hippocampal neuronal apoptosis in diabetic rats with depression by inhibiting JNK signaling pathway

Objective To investigate the effect of Zuogui Jiangtang Jieyu Formula(左归降糖解郁方,ZJJF)on hippocampal neuron apoptosis in diabetic rats with depression and to ascertain whether its mechanism involves the regulation of JNK signaling pathway.Methods(i)A total of 72 specific pathogen-free(SPF)grade male Sprague Dawley(SD)rats were randomly divided into six groups,with 12 rats in each group:control,model,metformin(Met,0.18 g/kg)+fluoxetine(Flu,1.8 mg/kg),and the high-,medium-,and low-ZJJF dosages(ZJJF-H,20.52 g/kg;ZJJF-M,10.26 g/kg;ZJJF-L,5.13 g/kg)groups.All groups except control group were injected once via the tail vein with streptozotocin(STZ,38 mg/kg)combined with 28 d of chronic unpredictable mild stress(CUMS)to establish diabetic rat models with depression.During the CUMS modeling period,treatments were administered via gavage,with control and model groups receiving an equivalent volume of distilled water for 28 d.The efficacy of ZJJF in reducing blood sugar and alleviating depression was evaluated by measuring fasting blood glucose,insulin,and glycated hemoglobin levels,along with behavioral assessments,including the open field test(OFT),forced swim test(FST),and sucrose preference test(SPT).Hippocampal tissue damage and neuronal apoptosis were evaluated using hematoxylin-eosin(HE)staining and terminal deoxynucleotidyl transferase-mediated dUTP nickend labeling(TUNEL)staining.Apoptosis-related proteins Bax,Bcl-2,caspase-3,and the expression levels of JNK/Elk-1/c-fos signaling pathway were detected using Western blot and real-time quantitative polymerase chain reaction(RT-qPCR).(ii)To further elucidate the role of JNK signaling pathway in hippocampal neuronal apoptosis and the pharmacological effects of ZJJF,an additional 50 SPF grade male SD rats were randomly divided into five groups,with 10 rats in each group:control,model,SP600125(SP6,a JNK antagonist,10 mg/kg),ZJJF(20.52 g/kg),and ZJJF(20.52 g/kg)+Anisomycin(Aniso,a JNK agonist,15 mg/kg)groups.Except for control group,all groups were established as diabetic rat models with depression,and treatments were administered via gavage for ZJJF and intraperitoneal injection for SP6 and Aniso for 28 d during the CUMS modeling period.Behavioral changes in rats were evaluated through the OFT,FST,and SPT,and hippocampal neuron damage and apoptosis were observed using HE staining,Nissl staining,TUNEL staining,and transmission electron microscopy(TEM).Changes in apoptosis-related proteins and JNK signaling pathway in the hippocampal tissues of rats were also analyzed.

左归降糖解郁方对糖尿病并发抑郁症大鼠海马血脑屏障精细结构AQP4、Cx43的影响

目的研究左归降糖解郁方(黄芪、贯叶连翘、姜黄、熟地黄、山茱萸等)对糖尿病并发抑郁症大鼠海马血脑屏障精细结构水通道蛋白AQP4和缝隙连接蛋白Cx43表达的影响。方法采用高脂乳剂灌胃、尾静脉注射链脲佐菌素、28 d慢性应激联合的方法复制糖尿病并发抑郁症大鼠模型,并随机分为5组:模型组,阳性药(二甲双胍+盐酸氟西汀)组,左归降糖解郁方高、中、低剂量组,以正常大鼠为空白组,灌胃给药4周。给药后,采用Morris水迷宫测试大鼠空间学习能力,HE染色法观察海马组织病理学,免疫组化法检测海马血脑屏障精细结构AQP4和Cx43表达情况。结果与空白组比较,模型组大鼠逃避潜伏期延长(P<0.01),海马细胞存在明显损伤,AQP4和Cx43表达下降,差异有统计学意义(P<0.05);与模型组比较,阳性药组和左归降糖解郁方高剂量组大鼠逃避潜伏期缩短,差异有显著统计学意义(P<0.01),海马细胞形态趋于正常,且AQP4和Cx43表达增多,差异有统计学意义(P<0.05)。结论左归降糖解郁方对糖尿病并发抑郁症大鼠的治疗作用可能与调控海马血脑屏障精细结构AQP4和Cx43表达有关。